Semiconductor devices and methods for depositing a dielectric film

ABSTRACT

Embodiments provide methods and apparatuses for chemical vapor depositing a dielectric film, and various structures, devices, and systems, which incorporate dielectric elements formed from the dielectric film. The method includes heating a chamber, within which a substrate is located, to a temperature sufficient to thermally decompose an oxidizing component. A gas flow is passed over the substrate to deposit the dielectric film. To form an oxide, the gas flow includes a silicon bearing component, the oxidizing component, and a chloride component. The silicon bearing component and the chloride component are distinct from each other. To form an oxynitride, the gas flow further includes an ammonia component. The silicon bearing component can be substituted by a tantalum bearing component or an aluminum bearing component, to form other types of oxynitrides.

TECHNICAL FIELD

The present invention relates generally to methods and apparatus forsubstrate processing, and more particularly to methods and apparatus forimproved deposition of dielectric films on a semiconductor substrate.

BACKGROUND

One process that is performed during the fabrication of a semiconductordevice is to form a dielectric film, such as silicon oxide (SiO₂) orsilicon nitride (SiN₂), on a semiconductor substrate. A thermal chemicalvapor deposition (CVD) process is sometimes used to deposit such films.In this process, reactive gases are supplied to a substrate surface, andheat-induced chemical reactions take place to produce the desired film.

Various combinations of reactive gasses have been used to producesilicon oxide and silicon nitride dielectric films. These combinationsgenerally include a silicon source and an oxidizing or nitridizingspecies. For example, dichlorosilane (SiH₂Cl₂), also referred to as DCS,has been used as a silicon source, and nitrous oxide (N₂O) has been usedas an oxidizing species. Ammonia (NH₃) has been used as a nitrogensource.

In a multi-wafer CVD system, multiple semiconductor wafers are loadedinto a reaction tube, the tube is heated, and the reactive gasses areintroduced at an entry point at a one end of the tube. The gasses passover the wafers and through the tube to an exit point. During thereaction, the DCS may be subjected to dissociation of hydrogen toproduce dichlorosilane (SiCl₂) and hydrogen (H₂) as shown in thefollowing equation (1).SiH₂Cl₂→SiCl₂+H₂  (1)At a high temperature, the chemical bond between the silicon atom andboth the two chlorine atoms and the hydrogen atom are subjected to theelimination of hydrogen and chlorine to make the silicon atom into a newsilicon atom terminated by the sole chlorine atom. Meanwhile, thermaldecomposition of the N₂O occurs all along the tube, and the thermaldecomposition of the N₂O is catalyzed by the chlorine by-product.

At the entry end of the reaction tube, the amount of chlorine gasavailable from the DCS decomposition is relatively small. Therefore, thedecomposition rate of the N₂O is simply characteristic of athermally-driven decomposition. However, further along the tube, ahigher concentration of chlorine exists as a by-product of the DCSdecomposition. The higher abundance of chlorine increasingly interactswith and enhances the decomposition and reaction of the N₂O, whichincreases the oxidation reaction rate. Accordingly, at the entry end ofthe tube, a more nitrogen rich environment exists, and toward the exitend of the tube, a more chlorine rich environment exists. This causes anon-stable reaction stoichiometry and rate from one end of the tube tothe other. The result is that oxide films deposited near the entry endof the tube are thinner than oxide films deposited further down thetube.

What are needed are methods and apparatus for depositing dielectriclayers in a more stable manner. Further needed are methods and apparatusfor stabilizing the reaction stoichiometry and the reaction rate invarious CVD systems, including CVD systems that utilize reaction tubes.

SUMMARY

In one embodiment, a method includes heating a chamber, within which asubstrate is located, to a temperature sufficient to thermally decomposean oxidizing component. A gas flow is passed over the substrate todeposit a dielectric film. The gas flow includes a silicon bearingcomponent, the oxidizing component, and a chloride component, which isdistinct from the silicon bearing component. In another embodiment, thegas flow includes a silicon bearing component, an oxidizing component,an ammonia component, and a chloride component, which is distinct fromthe silicon bearing component.

In still another embodiment, a method includes heating a siliconsubstrate, in a furnace deposition tube, to a temperature in a range of700 degrees C. to 950 degrees C., inclusive. The silicon substrate isthermally oxidized, in the furnace tube, using gaseous reactants. Thegaseous reactants include a chloride component, dichlorosilane, andnitrous oxide.

In still other embodiments, a semiconductor device, a memory array, amemory device, a semiconductor die, or an electronic system include asubstrate and a dielectric element. The dielectric element includes atleast a portion of a chemical vapor deposited dielectric layer formedfrom passing a gas flow over the substrate to deposit the dielectriclayer. The gas flow includes a silicon bearing component, an oxidizingcomponent, and a chloride component. The silicon bearing component andthe chloride component are distinct from each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic representation of a deposition systemsuitable for depositing a dielectric film, in accordance with anembodiment of the invention;

FIG. 2 illustrates a flowchart of a method for producing a dielectricfilm on a substrate, in accordance with an embodiment of the invention;

FIG. 3 illustrates a fragmentary, cross-sectional view of a genericsemiconductor device, partially formed in accordance with an embodimentof the invention;

FIG. 4 illustrates a fragmentary, cross-sectional view of a capacitivecomponent, partially formed in accordance with an embodiment of theinvention;

FIG. 5 illustrates a fragmentary, cross-sectional view of asemiconductor device having an oxide-nitride-oxynitride (ONO) stack,partially formed in accordance with an embodiment of the invention;

FIG. 6 illustrates a fragmentary, cross-sectional view of a stackedcapacitor, partially formed in accordance with an embodiment of theinvention;

FIG. 7 illustrates a fragmentary, cross-sectional view of asemiconductor device having a trench with an isolation liner, formed inaccordance with an embodiment of the invention;

FIG. 8 illustrates a fragmentary, cross-sectional view of a portion ofan optical waveguide, partially formed in accordance with an embodimentof the invention; and

FIG. 9 illustrates an electronic system, which includes at least onesemiconductor device, partially formed in accordance with an embodimentof the invention.

DESCRIPTION OF THE EMBODIMENTS

In the following description of the embodiments, reference is made tothe accompanying drawings, which form a part hereof and show, by way ofillustration, specific embodiments in which the invention may bepracticed. These embodiments are described in sufficient detail toenable those skilled in the art to practice the invention, and it is tobe understood that other embodiments may be utilized, and that processor mechanical changes may be made, without departing from the scope ofthe present invention. It will be recognized that the methods of thevarious embodiments can be combined in practice, either concurrently orin succession. Various permutations and combinations will be readilyapparent to those skilled in the art.

The various embodiments of the invention, described in detail herein,involve new and novel methods and apparatus for depositing dielectriclayers. The embodiments of the present invention have severalsignificant advantages over prior art methods. First, use of theembodiments of the invention result in deposition of dielectric layersin a more stable manner than is achieved using prior art methods.Further, use of the embodiments of the invention result in stabilizationof the reaction stoichiometry and the reaction rate in various CVDsystems.

FIG. 1 illustrates a schematic representation of a low pressure chemicalvapor deposition (CVD) system 100 suitable for depositing a dielectricfilm, in accordance with an embodiment of the invention. In variousembodiments, the system 100 is used to deposit an oxide film, a nitridefilm, and/or an oxynitride film on a substrate. In one embodiment,system 100 includes a reaction tube 110, gas sources 130, 132, 134, 136,138, valves 140, 142, flow controllers 144, 146, manifolds 150, 152, andpump 160.

Reaction tube 110 is a multi-wafer furnace deposition tube, in oneembodiment, oriented with its axis in a substantially verticaldirection, and having an inner chamber 112 and an outer chamber 114. Theinner chamber 112 is defined by an inner surface of an inner tube 116.The outer chamber 114 is defined by an outer surface of the inner tube116 and the inner surface of the reaction tube 110. Tube 110 is in arange of about 150–250 centimeters long, in one embodiment, with aninner diameter of about 12–20 centimeters. Longer or shorter tubeshaving larger or smaller inner diameters can be used in otherembodiments.

Prior to dielectric film deposition, one or more wafers 102 are loadedinto a multi-wafer carrier 118, the carrier 118 is loaded into the innerchamber 112, and the reaction tube 110 is sealed, as illustrated inFIG. 1. In one embodiment, carrier 118 includes a sufficient number ofslots to support from 100–200 wafers, although all of the slots need notbe filled during any particular reaction. Wafers 102 are typicallyapproximately 10 centimeters in diameter, although they can be larger orsmaller as well. Wafers 102 are supported in carrier 118 with theirmajor surfaces at right angles to the axis of the tube 110 and thedirection of gas flow. This arrangement permits a close-packed loadingwhich contributes to a potentially high wafer throughput of the system100.

In one embodiment, inert and reactive gasses are admitted to the tube110 at entry points 117, 119 at a first end 120 of the tube 110. Thegasses travel through the inner chamber 112 and over the wafers 102 in adirection indicated generally by arrow 170. At a second end 122 of thetube 110, the gasses are displaced toward the outer chamber 114, throughwhich they travel back toward the first end 120 of the tube in adirection indicated generally by arrows 172. The gasses are thenexhausted from the tube 110 at an exit point 124, and recovered by ascavenging system (not illustrated).

In an alternate embodiment, the reaction tube can have only a single,inner chamber, where the reaction gasses are input through an entrypoint at the first end 120 of the tube, and the gasses are exhaustedthrough an exit point at the second end 122 of the tube. In anotheralternate embodiment, the reaction tube can be a horizontally-orientedtube.

In still other embodiments, different types of single- or multi-waferreaction chambers can be used for the CVD process. For example, but notby way of limitation, the system can include one or more conductiveheating elements upon which the wafers are placed and heated prior tointroduction of the reactive gasses, in one embodiment. In still anotherembodiment, limited reaction processing (i.e. transient heating ratherthan furnace heating) can be used. In still another alternateembodiment, a plasma based CVD system can be used, where the reactiontemperatures may be cooler than the temperatures used in a thermal CVDsystem. A plasma enhanced CVD processes promotes the excitation and/ordissociation of reactant gases by the application of radio frequency(RF) energy to the reaction zone proximate a substrate surface. Thiscreates a plasma of highly reactive species. The high reactivity of thereleased species reduces the energy required for a chemical reaction totake place, and thus lowers the required temperature for such CVDprocesses.

Referring again to the embodiment illustrated in FIG. 1, reaction tube110 can include one or more thermal zones. In one embodiment, the tube110 includes five thermal zones, although more or fewer zones can beincluded in other embodiments. Using heating coils (not illustrated)associated with each zone, the temperature within each particular zonealong the tube can be independently controlled, permitting theattainment of a flat or graded temperature profile along the length ofthe tube 110. By varying the temperature within any zone, the reactionrate within that zone can be adjusted.

In one embodiment, the reaction gasses from sources 130, 132, 134, 136are admitted to manifold 150 via valves 140, respectively, and theirflow rates are controlled by mass flow controllers 144. Similarly, aninert gas from source 138 is admitted to manifold 152 via valve 142, andits flow rate is controlled by mass flow controller 146. The reactiongasses and inert gas are admitted to the tube 110 via manifolds 150,152, respectively.

In one embodiment, while forming an oxide layer, the reaction gassesinclude a silicon bearing component 130, an oxidizing component 132, anda chloride component 134. While the silicon bearing component 130 caninclude chloride, in various embodiments, the silicon bearing component130 and the chloride component 134 are distinct from one another,meaning that each component is a distinct reaction gas introduced intothe chamber. In other words, while chloride may (or may not) be abyproduct of the decomposition of the silicon bearing component 130, thechloride component 134 augments and is distinct from any such byproduct.In another embodiment, while forming an oxynitride layer, the reactiongasses also include an ammonia component 136. The inert gas includes anitrogen source 138, in one embodiment. Other inert gasses (e.g., argon,etc.) also can be included or alternatively used, in other embodiments.

FIG. 2 illustrates a flowchart of a method for producing a dielectricfilm on a substrate, in accordance with an embodiment of the invention.The method begins, in block 202, by preparing a substrate fordeposition. For example, the surface of the substrate can be etched orotherwise prepared. In one embodiment, the substrate is a silicon wafer,which may or may not have semiconductor structures formed thereon. Inother embodiments, the substrate can be a semiconductor such asgermanium, gallium arsenide or indium phosphide, an insulator such asglass or aluminum, or a metal such as stainless steel or iron.

In block 204, the substrate is then positioned within a carrier (e.g.,carrier 118, FIG. 1), alone or along with one or more other substrates.The carrier is inserted into the reaction tube (e.g., tube 110, FIG. 1)or other type of reaction chamber, at atmospheric pressure. The tube isthen sealed.

In one embodiment, the tube is then cycle purged, in block 206, to ridthe tube of contaminants. This process may involve several iterationsduring which the inert gas source (e.g., source 138, FIG. 1, which couldbe nitrogen, and/or argon, and/or another inert gas, for example) isalternatively turned on and off, and the pressure within the tube isvaried between low and relatively high values.

The tube integrity can then be checked, in block 208. In one embodiment,this involves turning the inert gas source off, reducing the tubepressure to a very low value (e.g., 50 millitorr), and performing a leakrate test to determine how fast the tube pressure rises.

Assuming the tube integrity is acceptable, the inert gas source isturned on, and the tube is temperature and pressure stabilized, in block210, for a period of time (e.g., 2 hours). In one embodiment, thepressure is set to a pre-reaction value, and the temperature is set to areaction value. In one embodiment, the pre-reaction pressure isapproximately 150 millitorr. The reaction temperature is a temperaturesufficient to thermally decompose the oxidizing component of thereaction gasses. In one embodiment, the reaction temperature is between700 and 950 degrees C., inclusive. In other embodiments, higher or lowervalues can be used, and/or the tube can be stabilized for a longer orshorter period of time.

The limitations on the reaction temperature range are based on the ideasthat, if the temperature is too low, growth will proceed so slowly thatit is uneconomic, or will stop altogether, and if the temperature is toohigh, free-space nucleation may occur, which will lead to particulateformation and degradation of the film quality.

The reaction gas manifold (e.g., manifold 142, FIG. 1) is then opened,at the pre-reaction pressure, and the reaction gasses are introducedinto the tube, in block 212. The gas flow passes over the substrateswithin the tube.

In one embodiment, the reaction gasses are introduced in the followingorder. First, oxidizing component (e.g., source 132, FIG. 1) isintroduced, and its concentration is permitted to stabilize for severalminutes. In one embodiment, the oxidizing component is gaseous nitrousoxide (N₂O). It is conceivable that other oxidizing species can besubstituted for nitrous oxide, while still preserving some of theadvantages of the invention. Second, the chloride component (e.g.,source 134) is introduced and permitted to stabilize. In one embodiment,the chloride component is hydrogen chloride (HCl), and in anotherembodiment, the chloride component is chlorine (Cl₂).

If an oxynitride film is being formed, then an ammonia component (e.g.,source 136) is then introduced, and permitted to stabilize. In oneembodiment, the ammonia component is ammonia gas (NH₃). If an oxide filmis being formed, an ammonia component is not introduced.

Finally, a precursor component (e.g., source 136) is introduced. Invarious embodiments, the precursor component can be selected from agroup consisting of a silicon bearing component, a tantalum bearingcomponent, and an aluminum bearing component, in any combination.

In one embodiment, the precursor component is a silicon bearingcomponent. The silicon bearing component can consist essentially of oneor more halated silanes. In one embodiment, the silicon bearingcomponent is selected from the group consisting of silane, disilane,monochlorosilane, dichlorosilane, trichlorosilane, andtetrachlorosilane, in any combination. Use of a silicon bearingcomponent will result in the deposition of a silicon dioxide film orsilicon oxynitride film (i.e., when ammonia is present).

In other embodiments, chlorosilanes which contain other halogen speciescan be substituted, wholly or partially, for the silicon bearingcomponents discussed above. Desirably, the gaseous silicon source isneither too stable nor too unstable. If the silicon source is toostable, excessively high growth temperatures may be required.Conversely, if the silicon source is too unstable, gas-phase nucleationmay occur, leading to particulate formation. Fluorinated chlorosilanes(e.g., SiH₃F) or bromine substitutions (e.g., SiHBrCl₂) can be used inalternate embodiments.

In other embodiments, the precursor component is a tantalum bearingcomponent or an aluminum bearing component. Use of such precursors willresult in the deposition of a tantalum oxynitride film or an aluminumoxynitride film, respectively (i.e., when ammonia is present).

In block 214, the pressure is raised to the reaction pressure. In oneembodiment, the reaction pressure is approximately 350 millitorr. Inother embodiments, the reaction pressure is in a range of about 50millitorr to 4000 millitorr, although higher or lower reaction pressurescan alternatively be used. For example, reaction pressures up to andpossibly exceeding 300 torr can be used in some embodiments. Theparticular reaction pressure chosen affects the deposition rate (i.e.,the deposition rate is lower at lower pressures). The limitation on thereaction pressure parameter comes from non-uniformity of deposition atvery low pressures, and from gas phase nucleation at very highpressures.

The CVD reaction then proceeds for an amount of time that is related tothe desired film thickness, in block 216. By allowing the reaction toproceed, the substrate is thermally oxidized using the gaseousreactants.

The various embodiments can be used to deposit and grow thin or thickfilms. The deposition/growth rate depends on the reaction parameters(e.g., pressures, temperatures, flow rates). In an embodiment where thereaction temperature is approximately 800 degrees C., the reactionpressure is 350 millitorr, and the ratio of hydrogen chloride to DCS isabout 3:1, the deposition rate is approximately 100 Angstroms/hour, inone embodiment. The rate can be higher or lower in other embodiments,depending on how the reaction parameters are varied.

In one embodiment, this completes the reaction. In another embodiment,further deposition processes can be performed while the wafers are stilllocated in the reaction tube. These further deposition processes can usethe same reaction gasses, or variations of the reaction gasses, todeposit various dielectric layers. For example, a material used in aconventional dynamic random access memory (DRAM) devices includes astack of an oxide layer, a nitride layer, and an oxynitride layer. Thisstructure is often referred to as an oxide-nitride-oxynitride or “ONO”structure. Using embodiments of the invention, blocks 212 and 214 can berepeated three times to form an ONO structure. During the first andthird iterations, when oxide layers are being formed, no ammonia ispresent in the reaction gasses. During the second iteration, while thenitride layer is being formed, ammonia can be introduced to the reactiongasses.

After the reaction is completed, the reaction is turned off, in block218, and the method ends. In one embodiment, this involves reducing thetemperature to a standby temperature (e.g., 600 degrees C.). Thereaction gasses are then turned off. In one embodiment, the precursorcomponent is first turned off, and the tube permitted to stabilize.Then, the ammonia component (if any), the chloride component, and theoxidizing component are sequentially turned off, allowing the tube tostabilize between the removal of each component. A cycle purge processis again performed, in one embodiment, to rid the tube of contaminants,and the tube is backfilled with an inert gas (e.g., nitrogen and/orargon). Ultimately, the wafers are withdrawn using a slow pull cycle toavoid exposure of the wafers to share temperature gradients. Desirably,the wafers are withdrawn to an ambient area free of oxygen, in order toprevent contaminants.

The ratios of the reaction gasses within the reaction gas flow can bevaried, in different embodiments. The following four tables providespecific reaction gas percentages (based on 100% total) for fourembodiments, and percentage ranges for each type of gas.

Table 1 illustrates a specific example of various reaction gaspercentages, and a range of gas percentages, for a silicon dioxide layerdeposited using hydrogen chloride.

TABLE 1 SiO₂ Deposited Using HCl Reaction gas Embodiment A Percentageranges DCS  5 2–10 HCl 15 5–50 N₂O 80 40–93 

Table 2 illustrates a specific example of various reaction gaspercentages, and a range of gas percentages, for a silicon dioxide layerdeposited using chlorine. Notice that, since each Cl₂ molecule includestwo chloride atoms (as opposed to one chloride atom for each HClmolecule), about half as much Cl₂ can be used to provide approximatelythe same amount of free chloride atoms as is used with HCl as thechloride source.

TABLE 2 SiO₂ Deposited Using Cl₂ Reaction gas Embodiment B Percentageranges DCS 5 2–10 Cl₂ 7.5 2–25 N₂O 87.5 65–96 

Table 3 illustrates a specific example of various reaction gaspercentages, and a range of gas percentages, for a silicon oxynitridelayer deposited using hydrogen chloride.

TABLE 3 SiON Deposited Using HCl Reaction gas Embodiment C Percentageranges DCS 5 2–10 HCl 15 5–50 NH₃ 5 2–10 N₂O 75 30–91 

Finally, Table 4 illustrates a specific example of various reaction gaspercentages, and a range of gas percentages, for a silicon oxynitridelayer deposited using chlorine.

TABLE 4 SiON Deposited Using Cl₂ Reaction gas Embodiment D Percentageranges DCS 5 2–10 Cl₂ 7.5 2–25 NH₃ 5 2–10 N₂O 82.5 55–94 

Although specific percentages and percentage ranges are given in thefour tables, above, percentages higher or lower than the listed rangescan be used in alternate embodiments. Further, DCS is shown as theprecursor source in the above examples. In other embodiments, varioushalated silanes (e.g., silane, disilane, monochlorosilane,dichlorosilane, trichlorosilane, tetrachlorosilane, and mixturesthereof) can be used. In still other embodiments, the precursor sourcecan be a tantalum precursor, an aluminum precursor, or some other typeof precursor.

The embodiments described herein can be used to form dielectric filmsfor a variety of applications. Generally, embodiments of the inventioncan be used in conjunction with nearly any electronic structure thatincludes a substrate over which at least one dielectric layer is formedusing a CVD process. The substrate can be a semiconductor, such assilicon, germanium, gallium arsenide, or indium phosphide.Alternatively, the substrate can be an insulator, such as glass oraluminum, or a metal, such as stainless steel or iron. The dielectriclayer or layers can be, for example, silicon dioxide, siliconoxynitride, tantalum oxynitride, aluminum oxynitride, other oxides,nitrides or oxynitrides, or any combination thereof. Besides thesubstrate and at least one dielectric layer, the electronic structurealso can include one or more conductive layers, semiconductor structures(e.g., gates, capacitors, etc.), and/or other insulating layers, whichcan be situated above and/or below the dielectric layer.

Various examples of electronic structures are illustrated in FIGS. 3–8.These examples are not to be construed as limiting the scope of theapplication only to these specific structures. Instead, these examplesare provided for the purpose of further illustrating various types ofapplications in which embodiments of the invention can be used. Those ofskill in the art would understand that embodiments of the invention canbe used in a wide variety of other applications, as well. Further, thespecific materials and structure described below are for the purposes ofillustration, and not of limitation. Those of skill in the art canimagine the use of different materials and/or structures, while stilltaking advantage of the embodiments of the present invention.

Specifically, FIGS. 3–7 illustrate various capacitive components, andFIG. 8 illustrates a portion of an optical waveguide. In addition to theillustrated components, embodiments of the invention can also be used inthe formation of semiconductor devices that include one or more gates,such as floating gate transistors and insulated gate transistors, forexample. In those embodiments, a dielectric layer deposited inaccordance with an embodiment of the invention can form one or morespacers for isolating the gates from contacts. Alternatively, adielectric layer deposited in conjunction with an embodiment of theinvention can form a cap over the gates and/or one or more metal layers.

Embodiments of the invention can be used to form numerous structuresthat include dielectric elements formed from all or portions of a CVDdeposited dielectric layer. These structures include both semiconductorand non-semiconductor structures and devices. In one embodiment, asemiconductor die is formed, which includes an integrated circuitsupported by a substrate. The integrated circuit can include a pluralityof integrated circuit devices with dielectric elements formed inaccordance with embodiments of the invention. In one embodiment, thedielectric element has a residual chlorine, meaning that chlorine is aby-product of the formation process of the dielectric element.

Components manufactured using embodiments of the invention can be usedin a wide variety of devices and systems. For example, such componentscan form various types of capacitive devices, memory cells, memoryarrays, memory devices, optical waveguides, processors, analog anddigital circuits, and other types of devices. A memory array can includea plurality of memory cells. A memory device can include a memory array,row and column access circuitry coupled to the memory array, and anaddress decoder coupled to the row and column access circuitry.

Referring now to specific examples, FIG. 3 illustrates a fragmentary,cross-sectional view of a first capacitive component, partially formedin accordance with an embodiment of the invention. The componentincludes a substrate 302, upon which a first dielectric layer 304 isformed. Layer 304 can be formed, for example, using a CVD process inaccordance with an embodiment of the invention.

A first wiring pattern 306 and/or electrode structure is then formedover the dielectric layer 304. The first wiring pattern 306 can beformed, for example, from a group of materials that includes polycide,polycrystalline silicon, silicide, various metals (e.g., molybdenum,tungsten, platinum, titanium, tantalum, zirconium, and palladium), othersuitable materials, or any combination thereof.

A second dielectric layer 308 is formed over the wiring pattern 306 andthe first dielectric layer 304. Layer 308 can be formed, for example,using a CVD process in accordance with an embodiment of the invention.Further, a second wiring pattern 310 and/or electrode structure isformed over the second dielectric layer 308. The capacitive component isconstituted by the first wiring pattern 306, the dielectric layer 308,and the electrode and wiring pattern 310.

FIG. 4 illustrates a fragmentary, cross-sectional view of a secondcapacitive component, partially formed in accordance with an embodimentof the invention. The capacitive component includes a substrate 402,upon which a first dielectric layer 404 is formed. Layer 404 can beformed, for example, using a CVD process in accordance with anembodiment of the invention.

An electrode layer 406 is then formed over the dielectric layer 404. Thefirst electrode layer 406 can be formed, for example, from a group ofmaterials that includes polycide, polycrystalline silicon, silicide,various metals, other suitable materials, or any combination thereof.

A second dielectric layer 408 is formed over the electrode layer 406.Layer 408 can be formed, for example, using a CVD process in accordancewith an embodiment of the invention. Then, a wiring pattern 410 and/orelectrode structure is formed over the second dielectric layer 408. Thecapacitive component is constituted by the electrode layer 406, thedielectric layer 408, and the electrode and wiring pattern 410.

FIG. 5 illustrates a fragmentary, cross-sectional view of asemiconductor device having an ONO stack, partially formed in accordancewith an embodiment of the invention. The ONO stack includes a substrate502, which can have semiconductor devices formed thereon. For example,but not by way of limitation, metal oxide semiconductor (MOS) devices(not shown) can be formed on the substrate 502. In other embodiments,the substrate can have other types of semiconducting upper portions.

A bottom electrode 504 is then formed on the substrate 502. The bottomelectrode 504 can be formed, for example, from a group of materials thatincludes polycide, polycrystalline silicon, silicide, various metals,other suitable materials, or any combination thereof In one embodiment,the bottom electrode 504 is disposed using a CVD process in an oxygencontained environment, so that a thin, native oxide layer (not shown) isallowed to form on the bottom electrode 504.

A nitride layer 506 is formed over the native oxide layer. Then, anoxynitride layer 508 is formed over the nitride layer 506. In oneembodiment, the oxynitride layer 508 is formed using a CVD process inaccordance with an embodiment of the invention.

The ONO structure is constituted by the native oxide layer, the nitridelayer 506, and the oxynitride layer 508. By repeating portions of theprocess described above, structures including additional O and N layerscan be formed to achieve different capacitor properties. For example,portions of the process can be repeated to form an ONONO structure, anONONONO structure, and so on.

FIG. 6 illustrates a fragmentary, cross-sectional view of a stackedcapacitor, partially formed in accordance with an embodiment of theinvention. The stacked capacitor includes a substrate 602, upon which afield oxide film 604 is formed. For example, when the substrate 602 issilicon, the field oxide film 604 can be formed by the local oxidationof silicon so as to provide electrical separation of the capacitor fromanother element.

A bottom electrode 606 is then formed. In one embodiment, the bottomelectrode 606 is deposited on the silicon region of the substrate 602opposite to the field oxide film region 604, by the selective growth ofpolycrystalline silicon so as to form the bottom electrode 606 of thecapacitor. In other embodiments, the bottom electrode 606 can be formed,for example, from a group of materials that includes polycide, silicide,various metals, other suitable materials, or any combination thereof.

A dielectric film 608 is deposited on the bottom electrode 606. Film 608can be formed, for example, using a CVD process in accordance with anembodiment of the invention.

A top electrode 610 is then formed. In one embodiment, the top electrode610 is deposited by the selective growth of polycrystalline silicon soas to form the top electrode 610 of the capacitor. In other embodiments,the top electrode 610 can be formed, for example, from a group ofmaterials that includes polycide, silicide, various metals, othersuitable materials, or any combination thereof.

FIG. 7 illustrates a fragmentary, cross-sectional view of asemiconductor device having a trench with an isolation liner (e.g., atrench capacitor), partially formed in accordance with an embodiment ofthe invention. The trench capacitor includes a substrate 702, upon whichan oxide film 704 is formed to electrically separate the capacitor fromother elements. For example, when the substrate 702 is silicon, and theoxide film 704 can be formed by thermal oxidation to form a siliconoxide film.

The oxide film 704 is then subjected to patterning, and the substrate702 is subjected to etching, so as to form a trench. A dielectric film706 is then deposited on an inner surface of the trench. Film 706 can bedeposited, for example, using a CVD process in accordance with anembodiment of the invention.

An electrode film 708 is then deposited and etched back, so thatportions of the electrode film 708 remain only within the trench. In oneembodiment, the electrode film 708 is formed from polycrystallinesilicon. In other embodiments, the electrode film 708 can be formed, forexample, from a group of materials that includes polycide, silicide,various metals, other suitable materials, or any combination thereof.

Embodiments of the invention also can be used to form portions of anoptical waveguide. An optical waveguide is a structure that guides alight wave by constraining it to travel along a certain desired path. Awaveguide traps light by surrounding a guiding region, referred to as a“core,” by a material having an index of refraction that is less thanthe core. This material is referred to as a “cladding.” Light can beguided by planar or rectangular waveguides, or by optical fibers, invarious embodiments.

FIG. 8 illustrates a fragmentary, cross-sectional view of a portion ofan optical waveguide, partially formed in accordance with an embodimentof the invention. The optical waveguide includes a first cladding layer802, which is formed from any of a number of cladding materials known tothose of skill in the art. For example, but not by way of limitation,cladding layer 802 can include silicon dioxide, and/or any of a numberof other suitable cladding layer materials.

A core layer 804 is formed over first cladding layer 802. In oneembodiment, core layer 804 includes one or more oxide and nitride layers(e.g., an ONO structure), which form at least a portion of a planarwaveguide core. All or portions of core layer 804 can be deposited, forexample, using a CVD process in accordance with an embodiment of theinvention. Core layer 804 may or may not be patterned during orsubsequent to its deposition.

A second cladding layer 806 is formed overlying film 804. For example,but not by way of limitation, second cladding layer 806 can includesilicon dioxide, and/or any of a number of other suitable cladding layermaterials.

Devices formed using various embodiments of the invention can form partof an electronic system. FIG. 9 illustrates an electronic system, inaccordance with an embodiment of the present invention. The system shownin FIG. 9 can be, for example, a computer, a wireless or wiredcommunication device (e.g., telephone, modem, cell phone, pager, radio,etc.), a television, a monitor or virtually any other type of electronicsystem that can benefit from the use of back side, cavity mountedcapacitors.

The electronic system includes one or more integrated circuits 902 andone or more memory devices 904. Integrated circuit 902 can be, forexample but not by way of limitation, a processor, application specificintegrated circuit (ASIC), or virtually any other type of integratedcircuit. Memory device 904 can be, for example but not by way oflimitation, a random access memory (RAM), dynamic RAM (DRAM), read onlymemory (ROM), any of a variety of derivations of RAMs and ROMs, or anyof a number of other types of memory devices. In various embodiments,the system can include numerous other types of electrical components,interconnects, power supplies, busses, ports, interfaces, printedcircuit boards, sockets, interposers, and other portions of anelectronic system. Integrated circuit 902 and/or memory device 908include electrical components, which include one or more dielectriclayers formed in accordance with various embodiments of the presentinvention.

Various embodiments of methods and apparatus for depositing dielectriclayers have been described, along with a description of theincorporation of the embodiments within an electronic system. Thevarious embodiments provide more stable deposition of dielectric layers.Further, the various embodiments provide improved stabilization of thereaction stoichiometry and the reaction rate in various CVD systems.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement that is calculated to achieve the same purpose maybe substituted for the specific embodiments shown. Many adaptations ofthe invention will be apparent to those of ordinary skill in the art.Accordingly, this application is intended to cover any adaptations orvariations of the invention. It is manifestly intended that thisinvention be limited only by the following claims and equivalentsthereof.

1. A method for depositing a dielectric film, the method comprising:heating a chamber, within which a substrate is located, to a temperaturesufficient to thermally decompose an oxidizing component; and passingreaction gasses over the substrate to deposit the dielectric filmforming a blanket dielectric deposition over substantially the entiretyof at least one surface of the substrate, wherein the reaction gassesinclude a silicon bearing component, the oxidizing component, and achloride component, and wherein the silicon bearing component and thechloride component are included within distinct ones of the reactiongasses introduced into the chamber.
 2. The method of claim 1, whereinthe dielectric film is an oxide film.
 3. The method of claim 1, whereinthe reaction gasses further includes ammonia, and the dielectric film isan oxynitride film.
 4. The method of claim 1, wherein the siliconbearing component consists essentially of one or more halated silanes.5. The method of claim 1, wherein the silicon bearing component includesat least one component selected from the group consisting of silane,disilane, monochlorosilane, dichlorosilane, trichlorosilane, andtetrachlorosilane, in any combination.
 6. The method of claim 1, whereinthe chloride component includes at least one component selected from thegroup consisting of hydrogen chloride and chlorine, in any combination.7. The method of claim 1, wherein the substrate is heated to atemperature in a range between 700 degrees C. and 950 degrees C.,inclusive.
 8. The method of claim 1, wherein the reaction gasses have atotal pressure in a range between 50 milliTorr and 4000 milliTorrinclusive.
 9. A method for depositing a dielectric film, the methodcomprising: heating a substrate, within a chamber, to a temperaturesufficient to thermally decompose an oxidizing component; and passingreaction gasses over the substrate forming a blanket dielectricdeposition over substantially the entirety of at least one surface ofthe substrate, wherein the reaction gasses include a silicon bearingcomponent, the oxidizing component, and chlorine, and wherein thesilicon bearing component and the chlorine are included within distinctones of the reaction gasses introduced into the chamber.
 10. The methodof claim 9, wherein the silicon bearing component consists essentiallyof dichlorosilane.
 11. The method of claim 9, wherein the oxidizingcomponent consists essentially of nitrous oxide.
 12. The method of claim9, wherein the reaction gasses further includes ammonia, and thedielectric film is an oxynitride film.
 13. A method for depositing adielectric film, the method comprising: heating a substrate, within achamber, to a temperature sufficient to thermally decompose an oxidizingcomponent; and passing reaction gasses over the substrate forming ablanket dielectric deposition over substantially the entirety of atleast one surface of the substrate, wherein the reaction gasses includea silicon bearing component, the oxidizing component, and hydrogenchloride, and wherein the silicon bearing component and the hydrogenchloride are included within distinct ones of the reaction gassesintroduced into the chamber.
 14. The method of claim 13, wherein thesilicon bearing component consists essentially of dichlorosilane. 15.The method of claim 13, wherein the oxidizing component consistsessentially of nitrous oxide.
 16. The method of claim 13, wherein thereaction gasses further includes ammonia, and the dielectric film is anoxynitride film.
 17. A method for depositing a dielectric film, themethod comprising: heating a substrate, within a chamber, to atemperature sufficient to thermally decompose an oxidizing component;and passing reaction gasses over the substrate forming a blanketdielectric deposition over substantially the entirety of at least onesurface of the substrate, wherein the reaction gasses include a siliconbearing component, the oxidizing component, an ammonia component, and achloride component, and wherein the silicon bearing component and thechloride component are included within distinct ones of the reactiongasses introduced into the chamber.
 18. The method of claim 17, whereinthe silicon bearing component consists essentially of dichlorosilane.19. The method of claim 17, wherein the oxidizing component consistsessentially of nitrous oxide.
 20. The method of claim 17, wherein thechloride component consists essentially of hydrogen chloride.
 21. Themethod of claim 17, wherein the chloride component consists essentiallyof chlorine.
 22. A method for depositing an oxynitride film, the methodcomprising: heating a substrate, within a chamber, to a temperaturesufficient to thermally decompose an oxidizing component; and passingreaction gasses over the substrate forming a blanket dielectricdeposition over substantially the entirety of at least one surface ofthe substrate, wherein the reaction gasses include a precursorcomponent, the oxidizing component, an ammonia component, and a chloridecomponent, and wherein the precursor component and the chloridecomponent are included within distinct ones of the reaction gassesintroduced into the chamber.
 23. The method of claim 22, wherein theprecursor component includes at least one component selected from thegroup consisting of a silicon bearing component, a tantalum bearingcomponent, and an aluminum bearing component, in any combination. 24.The method of claim 22, wherein the precursor component includes atleast one component selected from the group consisting of silane,disilane, monochiorosilane, dichlorosilane, trichlorosilane, andtetrachiorosilane, in any combination.
 25. The method of claim 22,wherein the precursor component consists essentially of a tantalumbearing component.
 26. The method of claim 22, wherein the precursorcomponent consists essentially of an aluminum bearing component.
 27. Themethod of claim 22, wherein the oxidizing component consists essentiallyof nitrous oxide.
 28. The method of claim 22, wherein the chloridecomponent consists essentially of hydrogen chloride.
 29. The method ofclaim 22, wherein the chloride component consists essentially ofchlorine.
 30. A method for fabricating a semiconductor device,comprising: heating a substrate, within a chamber; and depositing ablanket dielectric layer over substantially the entirety of thesubstrate by passing reaction gasses over the substrate, wherein thereaction gasses include a silicon bearing component, an oxidizingcomponent, and a chloride component, and wherein the silicon bearingcomponent and the chloride component are included within distinct onesof the reaction gasses introduced into the chamber.
 31. The method ofclaim 30, wherein the reaction gasses further includes an ammoniacomponent, and the dielectric layer is an oxynitride layer havingthermal properties that make the semiconductor device suitable for useas an optical waveguide.
 32. The method of claim 30, further comprising:etching a trench into the substrate, wherein the dielectric layer is anoxide deposited on an inner surface of the trench.
 33. The method ofclaim 32, further comprising: allowing a native oxide layer to formprior to depositing the dielectric layer; depositing a nitride layerover the native oxide layer prior to depositing the dielectric layer;and wherein depositing the dielectric layer includes also including anammonia component in the gas flow, so that the dielectric layer is anoxynitride layer.
 34. A method for fabricating a semiconductor device,comprising: heating a substrate; and depositing a dielectric layer overthe substrate by passing a gas flow over the substrate, wherein the gasflow includes a silicon bearing component, an oxidizing component, and achloride component, and wherein the silicon bearing component and thechloride component are distinct from each other, wherein thesemiconductor device includes one or more gates, and wherein thedielectric layer forms one or more spacers for isolating the one or moregates from one or more contacts.
 35. A method for fabricating asemiconductor device, comprising: heating a substrate; and depositing adielectric layer over the substrate by passing a gas flow over thesubstrate, wherein the gas flow includes a silicon bearing component, anoxidizing component, and a chloride component, and wherein the siliconbearing component and the chloride component are distinct from eachother, wherein the semiconductor device includes one or more gates andone or more metal layers, and wherein the dielectric layer forms a capover the one or more gates and the one or more metal layers.
 36. Amethod for forming a dielectric structure, the method comprising:heating a silicon substrate, in a furnace deposition tube, to atemperature in a range of 700 degrees C. to 950 degrees C., inclusive;and thermally oxidizing at least all non-insulator portions of thesurface of the silicon substrate, in the furnace tube, using gaseousreactants, which include a chloride component, dichlorosilane, andnitrous oxide, wherein the chloride component and the dichlorosilane areincluded in distinct gasses introduced into the furnace deposition tube.37. The method of claim 36, wherein the chloride component includeshydrogen chloride.
 38. The method of claim 36, wherein the chloridecomponent includes chlorine.
 39. The method of claim 38, whereinthermally oxidizing the silicon substrate further includes using ammoniaas one of the gaseous reactants.